Objective: Steam distillation extraction followed by gas chromatography-mass spectrometry (GC-MS) combined with quantification by peak area normalization method was used to analyze volatile compounds from leaf of Citrus erythrosa Tanaka. Method: Analysised bactericidal concentration of olatile compounds with the agar dilution method. Result: Showed that 36 compounds were identified with gc-ms

which the predominant compounds were r-elemene (30.691%)

β-caryophyllene (18.895%)

phellandrene (10.814%)

benzene-1-methyl-2-(1-meth-ylethy) (7.977%)

α-caryophyllene (5.260%) and α-farnesene (4.805%) et al. Results of experiments on antimicrobial activities showed that volatile component had antibacterial effects. Results Bacteriostatic test in vitro express that olatile oil to escherichia coli inhibitory effect in the most significant(MIC 3.9 g·L-1

MBC 5.6 g·L-1)

and followed by staphylococcus aureus

bacillus subtilis and candida. Conclusion: GC-MS could be used to identify and determine content of volatile components of leaf of C. erythrosa

and have a little of antimicrobial activity. This study could provide experimental basis for development and utilization of leaf of C. erythrosa.